Leg attachment system and method for seats

ABSTRACT

A system to attach seats, in particular rows of lightweight seats to the light gauge deck of a high passenger marine craft. Horizontal flanges of aluminum angles (23) form a T-shaped foot locking within cavity (35) of track (29) fixed to the deck. High tensile tie straps (27a, 27b) are held between the vertical webs of the angles (23) by pins (69). A tubular pedestal (25) has upper recesses (49) which mate with a box beam supporting the seats. Threaded studs (73)of the tie straps (27a, 27b) are bolted to the box beam so that inertial forces arising in the event of an impact of the craft will be uniformly distributed by the pedestal, tie straps (27a, 27b), and angles (23), to the track for dissipation over an extended length of track, thus reducing the effects of localized shear. On assembly of the system, the angles (23) need not to be slid along the track but may be inserted individually being later spaced apart by insertion of tie straps (27a, 27b) so as to laterally the cavity (35).

TECHNICAL FIELD

This invention relates to a leg attachment system and method for seatsattached to a seat support.

The invention has particular utility to the mounting of seats to thefloor of a vehicle or the deck of a vessel where the seats of thevehicle or vessel can be subjected to an appreciable lateral force whenthe motion of the vehicle or vessel is suddenly impeded.

The invention, however, is not limited to such application and hasgeneral utility as an attachment system for pedestals or standards ofany general form which are required to be anchored to a floor and whichmay be subject to the application of a lateral force.

BACKGROUND ART

In recent times, and with the application of new technologies, largepassenger carrying marine craft are achieving speeds of a magnitudenormally experienced in motor vehicles and so are capable of subjectingpassengers seated within them to high lateral forces which can causeserious injury if the motion of the vessel is suddenly impeded.

One of the problems with designing leg attachment systems for seating inmarine vessels, and which does not present itself to the same degree inrelation to land based vehicles, is the weight consideration whichseriously affects the design of the particular leg attachment systemthat is adopted. Moreover, in order to achieve high speeds, passengerferry craft are required to be light weight, whereby the weight of thevessel directly affects the maximum speed that can be obtained by thevessel. Consequently, passenger ferry craft these days are constructedwith decks of extremely light gauge material, for example aluminiumsheeting which can reach thicknesses of down to 2 mm. Consequently, theleg attachment systems that have previously been designed for seating toattach to decks of such light gauge material have similarly been oflight weight design and hence have skimped on meeting minimum safetystandards for resisting laterally applied impact forces.

An immediate solution to the problem would be to make leg attachmentsystems of heavier gauge material, however the inherent problem withthis is that this would considerably add to the weight of the vessel.

A further problem is that the beam of marine craft is not limited to thesame extent as the breadth of land based vehicles and hence there ismuch more flexibility in the positioning and the number of seats thatare able to be mounted upon a deck than is the case with land basedmotor vehicles. Hence, the ability to position seats easily andremovably is also an important design consideration which detracts fromhaving permanent fixed point anchoring systems for leg attachmentsystems, which are easier to design for meeting high loadingrequirements than is the case of impermanent anchoring points andfixtures.

Present types of anchoring techniques for leg attachment systems arebasically divided into three classes. The first is the flange or baseplate anchoring system as shown in FIG. 1A of the accompanying drawings,the second is the block mounted anchoring system as shown in FIG. 1B ofthe drawings, and the third is the track mounted anchoring system usingeither diamond or T-head bolts (not shown) or angle bolts shown in FIG.1C.

As shown in FIG. 1C, this system uses an interlocking angle `a` to whichtie bolts `b` are fixedly mounted to fixedly retain a seat pedestal leg`c` to a track `d`. The track `d` itself is permanently fixed to thedeck and is formed with a longitudinally extending cavity, centrallydisposed within and circumscribed by a C-shaped channel portion `e`.Such an arrangement has the advantage that the interlocking angle can bepositioned close to the installation site without having to be slidalong the entire length of deck track, which would otherwise be the caseif a captive T-head section was used. Although a T-head section wouldprovide greater locking ability and hence strength, as lengths of trackcan be as long as 50 m or more along a deck, such a system isimpractical to use.

The first two of these systems falls into the category of permanentaffixture anchoring points and is not attractive to the industry due tothe inability to change the fixing position of the leg attachment forthe seats, once it is fixed in position. A further problem is thatalmost all of the impact force is directly transferred to the deck ofthe vessel at the fixing point of the bolts, in the case of the flangeor base plate arrangement, and the blocks, in the block mountedarrangement. Such forces consequently impose considerable shear upon thedeck itself and in the case of lightweight thin gauge deck construction,the anchoring systems are able to pull out directly from the deck atrelatively low impact forces, causing permanent damage to the deckitself.

The track arrangement, however, is generally accepted as the industrystandard, whereby the track system allows for easy and impermanentpositioning of the anchoring means therealong, whilst causing the impactforces to be applied to the track itself rather than the deck.Accordingly, the track system allows the leg attachments for seats to beeasily slid into position, and the track itself can be attached to thedeck using various fixing systems, including rivet and nut inserts whichallow forces transmitted to the track to be more uniformly spread alongthe deck, reducing shear. In addition, the track provides a continuousattachment method for the leg attachments of the seats to the deck,where the leg attachments can be adjustably positioned at any time bysliding the legs in the track to the correct position.

Notwithstanding this improved arrangement, the two types of anchoringsystems used with the track arrangement, namely the diamond or T-headbolt anchoring system or the angle bolt anchoring system, have beenfound to be limited with respect to the size of the impact force thatcan be accommodated and fall short of the standards recently set by theInternational Maritime Organisation which are applicable to high speedpassenger carrying vessels.

Moreover, in the case of the diamond or T-head bolt arrangements, impactforces are still transmitted by the anchoring system to the track atpoint locations, consequently causing shearing of the anchoring meansfrom the track at these points. In the case of the angle bolt attachmentsystem, although impact forces are applied more uniformly along theangle, due to the limited ability of the angle to lock into the cavityof the C-shaped channel design of the track, the angle itself has atendency to pull out or shear from the track by the impact force,creating a bending moment around the flange or lip `f` of the trackwhich engages the flange of the angle.

Safety standards imposed by the International Maritime Organisation arecalculated in accordance with a vessel's "G" rating. Moreover, each typeof vessel has a "G" rating associated therewith which equates to thelikely inertial forces that may be applied to passengers, having regardto the vessel size, its speed and weight.

"G" ratings for most large passenger carrying marine craft require legattachment systems to resist impact forces in the region of 600 kg. Withrespect to the previously described prior art leg attachment systems,impact force resistance of only 300 kg to 400 kg can be achieved beforeexperiencing vertical separation of the leg attachment from the deck orthe track.

DISCLOSURE OF INVENTION

Accordingly, it is an object of the present invention to provide animproved leg attachment system which overcomes some or all of thedisadvantages associated with prior art leg attachment systems asdescribed above, and which in particular provides for opposing anddissipating impact forces of a magnitude to meet recent standardsadopted by the International Maritime Organisation.

In accordance with one aspect of the present invention, there isprovided a leg attachment for seats mounted to a seat support,including:

an anchoring means for lockingly engaging a base having a track therein,said base being fixedly mounted to a support;

leg means for surmounting said anchoring means and supporting a seatsupport thereon; and

tie means for released fixed attachment to said anchoring means at oneend and clamped locking engagement to the seat support at the other end,such that increased locking engagement of said tie means with the seatsupport positively locks said leg means to said anchoring means;

wherein lateral forces applied to the seat support are transferred bysaid leg means and said tie means to said anchoring means, whilstsimultaneously being disseminated through said leg means;

and wherein said anchoring means is adapted to dissipate the forcetransferred thereto uniformly over an expansive portion of the trackbase

Preferably, said anchoring means comprises a pair of interlockingangles, each having an outer flanged end, for being positively engagedwithin a longitudinally extending cavity centrally disposed within andcircumscribed by a C-shaped channel portion of the track, and asubstantially planar web portion for projecting outwardly from thecavity; wherein said flanged ends combinedly define a T-shaped foot forlocking engagement within the cavity and said web portions define a legfor attachment to said tie means, when said interlocking angles arebrought into juxtaposition with each other.

Preferably, the combined transverse extent of said flanged ends ismarginally less than the corresponding maximal transverse extent of thecavity, and the combined transverse extent of the web portions proximateto said foot is marginally less than the minimal transverse extent ofthe cavity, so that said interlocking angles are required to betransversely spaced apart a prescribed distance to fully occupy andengage said cavity when in said juxtaposition, to enable oneinterlocking angle to be discretely withdrawn from engagement with thetrack by lateral rotation thereof relative to the other interlockingangle.

Preferably, said web portions are each provided with a correspondingtransversely extending aperture to facilitate attachment to said tiemeans.

Preferably, said leg means comprises a tubular pedestal having a baseend for sitting upon the track whilst surmounting said anchoring means,and an opposing support end formed with a transversely extending recessof complementary shape to the seat support to accommodate a longitudinalportion of the seat support, transversely across said pedestal.

Preferably, said tie means comprises a shank portion for extending alongand within said tubular pedestal, said one end having a transverselyextending aperture for aligning with corresponding apertures of saidanchoring means to facilitate attachment thereto.

Preferably, said other end of said tie means is formed with a screwthreaded fastening means for locating within a corresponding aperturedisposed upon the support beam and for clampingly and lockingly engagingthe seat support positively upon said tubular pedestal within saidrecess on increased locking engagement of said fastening means upon theseat support.

Preferably, said one end is able to be releasedly pinned to saidanchoring means by means of a pin inserted through the correspondingapertures of said web portions and said one end when brought intorelative axial alignment.

Preferably, said shank portion comprises a strap of commensuratetransverse extent at said one end to said prescribed distance for beingdisposed interposedly between said web portions, so as to maintainlocking engagement of said foot with the track.

In accordance with another aspect of the present invention, there isprovided a leg attachment system for seats mounted to a seat support,comprising:

a base having a track for fixed mounting to a support; and

a leg attachment including:

(i) an anchoring means for lockingly engaging said track;

(ii) leg means for surmounting said anchoring means and supporting aseat support thereon; and

(iii) tie means for released fixed attachment to said anchoring means atone end and clamped engagement to the seat support at the other end,such that increased locking engagement of said tie means with the seatsupport positively locks said leg means to said anchoring means;

wherein lateral forces applied to the seat support are transferred bysaid leg means and said tie means to said anchoring means, whilstsimultaneously being disseminated through said leg means;

and wherein said anchoring means is adapted to dissipate the forcetransferred thereto uniformly over an expansive portion of said base.

In accordance with another aspect of the present invention, there isprovided a method of forming a demountable leg attachment system forseats, comprising:

fixedly mounting a base having a track therein to a support;

inserting anchoring means into said track to lockingly engage therewith;

releasedly attaching tie means to said anchoring means, so that said tiemeans can project upwardly therefrom;

surmounting a leg means for supporting a seat support, over saidanchoring means so that said tie means is disposed within the confinesof the leg means and can extend therealong;

positioning a seat support upon the top of said leg means and locatingthe ends of said tie means to extend through said seat support;

clampingly engaging said seat support to said leg means by lockingengagement of said tie means with said seat support, and consequentlyclampingly engaging said leg means upon said track;

wherein lateral forces applied to said seat support are transferred bysaid leg means and said tie means to said anchoring means, whilstsimultaneously being disseminated through said leg means;

and wherein forces transferred to said anchoring means are dissipateduniformly over an expansive portion of said base.

In this manner, leg attachments and hence seats can be positioned at anylocation along long lengths of deck track without having to slidecaptive T sections from one end, whilst maintaining maximum resistanceto vertical separation of the anchoring system from the track.

BRIEF DESCRIPTION OF DRAWINGS

The invention will be better understood in the light of the followingdescription of three specific embodiments thereof. The description ismade with reference to the accompanying drawings, wherein:

FIGS. 1 and 1a-1c is a perspective view showing a pair of seats mountedupon the leg attachment system of the present invention;

FIG. 2 is an exploded perspective view showing how a seat support beamis mounted to the leg attachment system of the first embodiment;

FIG. 3 is a fragmentary perspective view showing the leg attachmentsystem of the first embodiment;

FIG. 4 is a top sectional view of the leg attachment taken along section4--4 of FIG. 3;

FIGS. 5a, 5b, 5c and 5d are a set of sectional end views showing themethod by which the anchoring means and tie means are inserted into atrack to form part of the leg attachment system in accordance with thefirst embodiment;

FIG. 6 is a similar view to FIG. 2, but of a leg attachment system inaccordance with the second embodiment;

FIG. 7 is a similar view to FIG. 3, but of a leg attachment system inaccordance with the second embodiment;

FIG. 8 is a similar view to FIG. 4, but taken along section 8--8 of FIG.7;

FIG. 9 is a fragmentary sectional side view of a fully assembled legattachment system in accordance with the third embodiment;

FIG. 10 is a sectional end view of the leg attachment system shown inFIG. 9;

FIG. 11 is a side elevation of the pair of flanged plates in accordancewith the third embodiment;

FIG. 12 is an end view of the flanged plates shown in FIG. 11;

FIG. 13 is a plan view of the flanged plates shown in FIG. 11;

FIG. 14 is side elevation of the tie means in accordance with the thirdembodiment;

FIG. 15 is a fragmentary side elevation of the tie means shown in FIG.14;

FIG. 16a is a side elevation of a preform metal strap in accordance withan alternative embodiment;

FIG. 16b is a plan view of FIG. 16a;

FIG. 17 is a plan view of a preform metal strap in accordance withanother alternative embodiment;

FIG. 18a is a diagrammatic side elevation showing the interconnection ofan anchoring means and a tie means using a deformable pin arrangement asdescribed in another modified embodiment;

FIG. 18b is an end view of 18a; and

FIG. 19 is a similar diagrammatic view to FIG. 16a but depicting anarrangement using pins in deformable slots.

SPECIFIC EMBODIMENTS OF THE INVENTION

In the description of the embodiments and drawings associated therewith,the same reference numerals have been used to identify common featuresof the embodiments.

As shown in FIG. 1 of the drawings, all of the embodiments are directedtowards a demountable leg attachment system for attaching rows oflightweight seats 11 to the deck 13 of a high speed passenger marinecraft, via a seat support beam 15 which has the seats fixedly attachedthereto. The beam 15 is supported by two or more pedestal legs 17 whichare in turn lockingly engaged with respective bases 19 comprising trackswhich run longitudinally and are fixedly attached to the deck 13 of thevessel.

The first embodiment is directed towards a demountable leg attachmentsystem 21 comprising an anchoring means in the form of a pair ofinterlocking angles 23, leg means in the form of a tubular pedestal 25,tie means in the form of a 15 pair of tie straps 27, a base comprising atrack 29 and a seat support beam 31.

The track 29 is of the conventional extruded aluminium form having aC-shaped channel portion 33 centrally disposed therein and defining andcircumscribing a longitudinally extending cavity 35 therein. The track29 is also provided with a pair of outwardly projecting longitudinallyextending flanges 37, each having a proximal planar portion 37a and adownturned distal portion 37b. The proximal portions 37a respectivelydefine inwardly projecting flanges or lips 39 which are spaced apart aprescribed distance in opposing relationship to define an opening intothe cavity 35 of the track. The distal portions 37b have a downwardextent commensurate to the height of the C-shaped channel to engage thedeck lining in conjunction with the bottom of the C-shaped channel 33which engages the deck itself. Accordingly, the distal portions 37bprovide a clean finish for carpet or other deck covering whichterminates adjacent to the channel 33.

The track 29 is fixedly attached to the deck by screws, rivets, weldingor other fastening arrangement.

The seat support beam 31 is also of conventional extruded aluminiumform, comprising a trapezial box channel portion 41 and a planar flangedmounting portion 43, contiguous with the long and parallel side of thechannel portion.

The opposing sides of the mounting portion 43 comprise longitudinallyextending flanged ends 43a to facilitate attachment to the legattachment system in a manner to be described later.

The mounting portion 43 provides a surface to which the seats 11 arefixedly mounted by a nut and bolt fastening arrangement or the like andthe boxed channel portion 41 is disposed to depend from the mountingportion 43 to surmount the pedestal 25. Accordingly, the support beam 31is disposed transversely of a series of seats 11 disposed side by sideas shown in FIG. 1 of the drawings for attachment thereto.

The tubular pedestal 25 is of substantially rectangular extrudedaluminium form having a pair of opposing side panels 45 which areinterconnected by a pair of opposing end panels 47. The opposing axialends of the pedestal are terminated in planes which are obliquelydisposed relative to the axial extent of the pedestal so that the top ofthe pedestal projects forwardly when seated upon its base end and thetop end is inclined downwardly towards the rear of the pedestal.

The side panels 45 have corresponding recesses 49 formed therein ofcomplementary shape to the trapezial box channel portion 41 in sectionso that the support beam 31 can be accommodated therein in a transverserelationship with respect to the pedestal. The recesses 49 are centrallydisposed between he end panels 47 and terminate marginally therefrom todefine a pair of opposing end landings 51a and 51b which provide a seatfor the opposing flanged ends 43a and 43b of the seat mounting portion43.

The corners of the panels 45 and 47 are truncated so that thelongitudinal sides 48 of both end panels function to facilitate locatingthe pedestal 25 laterally relative to the tie straps 27 to enable thepedestal to be locked centrally upon the track 29 in a manner thatshould become apparent later. This facility is of more importance to thesecond embodiment and will be described in more detail in relation tothat embodiment.

The posterior end panel 47a has a rectangular aperture 50 formed thereinwhich is disposed a prescribed distance from the bottom end of thepedestal to enable interlocking engagement with the interlocking anglesin a manner to be described later. The anterior end panel 47b is formedwith a rectangular recess 52 at the bottom end of the pedestal whichextends along the end panel a prescribed distance from the bottom edgeto terminate at a prescribed height above the bottom end of the pedestalcorresponding to the tope of said interlocking angles thereat.Accordingly, the recess 52 is sized to accommodate the interlockingangles 23 in a position so that the pedestal 25 can surmount both theangles simultaneously with the bottom end of the pedestal siftingsymmetrically upon the proximal planar portion 37a of the track.

The interlocking angles 23 are formed of aluminium plate and each areprovided with a longitudinally extending flanged end portion 53 and anelongated web portion 55. The length and height of the angles 23 isdetermined in accordance with impact force resistance calculations, andin the present embodiment, the length is longer than the distancebetween the end panels 47 of the pedestal 25. The posterior end 57 ofthe interlocking angles 23 is obliquely angled relative to thelongitudinal extent of the flanged end portions 53 and is parallel withthe panel ends 47 of the pedestal 25, when the pedestal is correctlydisposed upon the track 29.

As shown in FIG. 3 of the drawings, the posterior end 57 is stepped todefine an outwardly projecting tongue 59 which is correspondingly sizedto repose within the posterior aperture 50 of the pedestal. The anteriorends 61 of the interlocking angles 23 are each tapered from theposterior end 57 a distance marginally greater than the distance betweenthe end panels 47 of the pedestal. The tapering is provided to reduce onthe amount of material involved with forming the interlocking angles 23,without unduly sacrificing on strength, and furthermore mitigates theobtrusive nature of the interlocking angles 23 extending anteriorly ofthe leg attachment system, and avoids the presence of any sharp edges onwhich people may catch themselves moving to or from the seats.

The web portions 55 are provided with a plurality of apertures whichextend transversely therethrough and which are correspondingly alignedwhen the angles are disposed in juxtaposed corresponding relationshipwith each other. Two of the apertures 65 are disposed towards theposterior end 57 of the interlocking angles 23 and one aperture 67 isdisposed intermediate of the web portion 55 a prescribed distance fromthe aperture 65 which is less than the spacing between the end panels47.

Importantly, the flanged ends 53 of the interlocking angles 23 define aT-shaped foot for locking engagement within the cavity 35 when theflange plates are brought into juxtaposition with each other. Further,the combined transverse extent of the flanged ends 53 is marginally lessthan the corresponding maximal transverse extent of the cavity 35. Inaddition, the combined transverse extent of the web portions 55,proximate to the foot, is marginally less than the minimal transverseextent of the cavity which corresponds to the opening disposed betweenthe lips 39 of the track 29. The significance of this will be describedin further detail later.

The tie straps 27 are formed of an appropriate high tensile steel andcomprise a shank portion 71 and a threaded bolt stem 73 connectedthereto. The bottom end of the shank portion is obliquely angledrelative to the longitudinal axis of the strap for engaging the bottomof the C-shaped channel portion 33 of the track 29. The bolt stem 73 iswelded to the other end of the shank portion and forms part of a screwthreaded fastening means for affixing to the support beam 31. The otherpart of the fastening means comprises bolt fasteners 75 and washers 77which are corresponding sized to screw upon the threaded bolt stems 73.

The length of the shank portion 71 is marginally less than the length ofthe pedestal 45 and the bolt stems 73 project longitudinally from theouter ends of the shank portion 71 at an attitude which is orthogonal tothe plane of the top end of the pedestal, defined by the landings 51aand 51b when correctly positioned within the pedestal.

The bottom ends of the shank portions 71 are provided with apertures(not shown) to align with the apertures 65 and 67 of the interlockingangles 23 respectively. Moreover, the posterior tie strap 27a isintended to be disposed towards the rear of the pedestal 25 and isprovided with two apertures which are disposed along the shank portion71 at corresponding distances from the bottom end of the shank portionas are the rear apertures 65 relative to the bottom of the interlockingangles 23. In this manner, the apertures 65 and the correspondingapertures of the posterior tie strap 27a can be aligned in position whenthe tie strap 27a is disposed within the cavity 35, together with theinterlocking angles 23.

The anterior tie strap 27b is intended to be disposed towards the frontof the pedestal 25 and is provided with an aperture disposed along theshank portion 71 thereof at a corresponding distance from the bottom endof the shank portion as are the apertures 67 relative to the bottom ofthe interlocking angles 23 thereof. Consequently, the correspondingaperture 67 and the aperture of the tie strap 27b can be aligned whenthe tie strap 27b is disposed in the cavity 35 in conjunction with theinterlocking angles 23.

Accordingly, the apertures 65 and 67 of the interlocking angles arecorrespondingly sized with respect to the apertures of the tie straps 27so that when aligned, respective pins 69 are able to be inserted throughthe web portions and the straps transversely to releasedly pin thestraps to the angles.

The relative positioning of the apertures 65 and 67 along theinterlocking angles 23 is precisely determined so that the rearlongitudinal edge 71a of the posterior tie strap 27a is disposed incorresponding angular relationship relative to the track 29 as is theposterior end panel 47 of the pedestal when the pedestal 25 is mountedon the track itself. That is, the rear longitudinal edge 71a of the tiestrap is disposed in parallel relationship to the end panel 47.

Further, the relative longitudinal spacing of the apertures 65 and 67along the web portions 55 is such that when the tie straps 27 are pinnedto their corresponding apertures, and the anterior tie strap 27b isdisposed in parallel relationship to the posterior tie strap 27a, thedistance between the rear longitudinal edge 71a of the posterior tiestrap 27a and the anterior longitudinal edge 71b of the anterior tiestrap 27b is commensurate to the spacing between the end panels 47 ofthe pedestal. Further, the combined transverse extent of the webportions 55, as spaced apart by the tie straps 27, is commensurate tothe transverse extent of the end panels 47 between the longitudinalsides 48 thereof, and the longitudinal extent and spacial positioning ofthe pins 69 is similarly commensurate to the corresponding transverseextent of the adjacent portions of the truncated corners of the pedestal25. In this manner, the pedestal 25 can be fitted upon the assembled tiestraps and interlocking angles to surmount the angles and automaticallyalign the tie straps 27 in parallel and juxtaposed relationship with theend panels 47 of the pedestal, as well as symmetrically locate upon thetrack 29 and lock in the pins and interlocking angles in position.

The bolt stems 73 consequently are disposed apart in parallelrelationship a prescribed distance, when the tie straps are assembledinto position. This enables correspondingly spaced bolt holes 79 to bedisposed within the opposing flanged ends 43a of the support beam 31 andthe bolt stems 73 to be inserted therethrough when the support beam 31is correctly positioned upon the pedestal 25.

Consequently, the support beam 31 can be positively locked into positionon the pedestal 25 by screwing the nut fasteners 75 together withwashers 77 onto the threaded bolt stems 73.

Now describing the method of assembling the leg attachment system, theinterlocking angles 23 are inserted into the track one at a time, asshown in FIGS. 5b and 5c by disposing the flanged end 53 of an angle inparallel alignment with the cavity 35, and hooking the flanged end 53under the corresponding lip 39 of the track, rotating the plate aroundthe lip as is necessary. Accordingly, the thickness of the web portions55 and the dimensioning of the C-shaped channel portion needs to be suchas to allow sufficient clearance between the angles to allow thisdiscrete hooking engagement with the corresponding lip, whilst the otherangle is disposed in its locking position, as shown in FIG. 5c of thedrawings.

After both plates 23 are engaged within the track, they are transverselyspaced apart a distance commensurate to the thickness of the bottom endsof the shank portions 71 of the tie straps 27. Accordingly, the flangedends 53 may be provided with a stepped edge 54 to fully occupy andengage the cavity when in juxtaposed spaced apart relationship to eachother, to accommodate the shank portion of the strap, as shown in FIG.5d of the drawings.

The tie straps are disposed so that the bottom end of the shank portions71 engage the bottom of the channel portion 33 and the correspondingapertures 65 and 67 of the flange plates are aligned with thecorresponding apertures of the straps so that the pins 69 can beinserted therethrough to fixedly attach the straps to the plates.

At this position, the posterior tie strap 27a generally adopts its finalposition, however the anterior tie strap 27b may be able to pivot tosome degree about its single pin.

The pedestal 25 is then positioned so that the top of the tie straps areinserted through the tubular confines of the pedestal 25 from the bottomend thereof, whereby due to the precise positioning of the pins andapertures, the anterior tie strap will pivot around its pin 69 so thatthe anterior longitudinal edge 71b thereof moves into parallelengagement with the anterior end panel 47b as the bottom end of thepedestal is progressively moved towards and ultimately engages the track29.

Importantly, the tongues 59 of the interlocking angles 23 simultaneouslyengage the rectangular aperture 50 of the posterior end panel 47a, andthe leading end of the interlocking angles extend through the recess 52of the anterior end panel 47b as shown in FIGS. 2 and 3 of the drawings.

Importantly, the geometry of the pin and aperture positions togetherwith the positioning and sizing of the bolt straps and pedestal,automatically causes the engagement between the tongue and the apertureand the parallel arrangement of the tie straps so as to minimise thelikelihood of human error in the assembly operation.

At this position, the support beam 31 is then disposed so that the boltholes 79 are aligned with the bolt stems 73 and the trapezial boxchannel portion 41 is positioned to sit within the complementaryrecesses 49 of the pedestal. The nut fasteners 75 and washers 77 canthen be inserted and screwed upon the bolt stems 73, clamping thesupport beam 31, 15 and pedestal 25 into position.

It is important to note that the foot of the interlocking angles 23fully occupies the cavity 35 of the channel portion 33 of the track tomaximise locking engagement with the inner lips 39 of the track, whichallows not only increased locking engagement of the support beam andpedestal with the track but also maximises the ability of the legattachment to resist the application of lateral forces thereto.

The demounting of the leg attachment system is achieved by simplyperforming the reverse process to the assembly operation.

The operation of the leg attachment system in resisting inertial forcesgenerated by seat components and occupants acting upon such componentswhen the forward momentum of the vessel is suddenly impeded, as wouldoccur in a collision, will now be considered. In such a circumstance,the normal tendency of the leg attachment is to move forwardly about itsanchoring points. In the present embodiment, such tendency to moveforwardly is opposed by the pin arrangement of the posterior strap, theengagement between the posterior end panel 47a and the posterior tiestrap 27a, the engagement between the anterior end panel 47b and theanterior tie strap 27b, and the engagement of the tongue with the bottomedge of the aperture 50. Thus, the anchoring means, pedestal and tiemeans are all held together and are able to resist vertical movementduring application of a lateral force directed at the level of the seatby dissipating the force uniformly through each of these components andnot just concentrating the force upon the tie means, as is the case withprior art systems.

Accordingly, there is a reduced tendency to allow small movements of thetie straps which would otherwise tend to change the geometricarrangement of the components, causing an increased load to be placedupon the tie straps for the same external load, increasing shear forces.

In addition, the length and height of the flange plates is increasedcompared with prior art systems so that the leading ends of theinterlocking angles protrude forwardly through the recess 52 to providean increased engagement length of the anchoring means with the track,whilst maintaining feet clearance for seat occupants of the seatsbehind. This configuration provides an increased capacity of the legattachment to resist dislodgement forces during a vessel impact withoutsignificantly increasing the weight of the attachment.

By virtue of the leg attachment system of the present embodiment,extremely high impact resistance loadings can be achieved, in excess of2,100 kg. Accordingly, the present embodiment represents a vastimprovement over prior art leg attachment systems.

The second embodiment is substantially similar to the first embodimentexcept that it is directed towards a demountable leg attachment systemas shown in FIGS. 6 and 7, which has an anchoring means confined to theinside of the pedestal for aesthetic, purposes and for applicationswhere impact force resistance requirements are not as great to conformwith safety requirements.

As shown in the drawings, the track, support beam, pedestal and tiestrap components of the system are substantially identical to those ofthe previous embodiment. The anchoring means, however, comprises a pairof shortened interlocking angles 81 of commensurate length to thespacing between the end panels 47 of the pedestal 25. Accordingly, theinterlocking angles omit the provision of a tongue and a leadingprotruding end thereof, and the pedestal omits the posterior aperture 50and the anterior recess 52 thereof. Apart from this, the anchoring meansis identical to that of the preceding embodiment.

With the omission of the aforementioned components from the interlockingangles and the pedestal, the configuration of the end panels 47 and thetruncated corners thereof become pre-eminent in locating the pedestalcentrally upon the interlocking angles, the straps and track, andlocking in the pins, web portions and straps during assembly. In thisrespect, the opposing ends of the web portions sit in abuttingengagement with the adjacent planar portions of the end panels so thatthe longitudinal sides 48 are each disposed adjacent to the outertransverse extent of the spaced web portions at each end thereof,thereby centrally and symmetrically locating the pedestal upon thetrack.

Although this type of leg attachment system cannot achieve the sameimpact resistance loads as is the case of the previous embodiment, itstill is a vast improvement upon prior art systems, whereby loadings inthe order of 1,500 kg are still able to be achieved by this embodiment.

The third embodiment is directed towards a leg attachment system havingan alternative form of anchoring means and tie means, as shown in FIGS.9 to 15 of the drawings.

In this embodiment, the anchoring means comprises a pair of interlockingangles 91 which are of a greater thickness than is the case of theinterlocking angles of the preceding embodiments, so as to fully occupythe cavity of the track when disposed in juxtaposed relationship withrespect to each other as shown in FIG. 10 of the drawings.

In order to achieve this juxtaposed positioning of the interlockingangles, the angles have to be inserted serially of each other along thetrack and then be slid along the track together to adopt the juxtaposedcorresponding position as shown in FIG. 9 of the drawings.

Furthermore, both of the interlocking angles 91 have a longitudinalextent greater than the spacing between the end panels 47 of thepedestal, as in the case of the first embodiment, however instead ofbeing formed with a tapered leading end, the angles are formed with arearwardly protruding tapered tail portion 93.

Consequently, the pedestal is formed with a posterior recess 95 withinthe posterior end panel 47a along the bottom edge thereof to accommodatethe rearward extension of the interlocking angles through the pedestal.

The leading ends 97 of the interlocking angles are obliquely disposedrelative to the bottom longitudinal edge thereof to adopt a parallelrelationship, when fitted into position, with the anterior end panel 47bof the pedestal. Accordingly, the inner face of the anterior end panel47b is able to be brought into butting relationship with the leadingends 97 of the interlocking angles, as shown in FIG. 9 of the drawings,when assembled.

The web portions 94 of each of the interlocking angles 91 are eachprovided with a single corresponding aperture 98 disposed at anintermediate position between the anterior end 97 and the tail portion93 so as to be disposed within the confines of the pedestal whenassembled. Accordingly, when the interlocking angles 91 are juxtaposedin corresponding relationship, the apertures 98 of each of the anglesare disposed in axial alignment.

The tie means comprises anterior and posterior ties.

The posterior tie comprises a shank portion 99, a U-shaped bracket 101fixedly mounted to the bottom of the shank portion 99, and a threadedend 103 which forms part of a threaded fastener, the other partcomprising a fastener nut 105 and washer 107 as shown in FIG. 12 of thedrawings. The U-shaped bracket 101 has a pair of transversely extendingapertures 109 disposed therein of corresponding size to the apertures 98of the interlocking angles. Accordingly, the U-shaped bracket 101 isadapted to surmount the top of the flange plates when disposed in theircorresponding juxtaposed position so that the aperture 109 thereof canbe disposed in axial alignment with respect to the apertures 98 of theinterlocking angles.

Consequently, a removable pin 111 is provided to be inserted axiallythrough the aligned apertures to pivotally and fixedly attach theposterior tie means to the anchoring means.

The anterior tie means comprises a mounting bolt 113, which has a curvedthreaded bolt stem 115 connected to the top of the anterior end panel47b, to project outwardly from the top of the pedestal 25, orthogonallyof the plane of the top of the pedestal.

Similarly, the top of the shank portion 99 is curved so that thethreaded end 103 adopts an axial position which is disposed parallel tothe threaded stem 115 of the mounting bolt 113. The mounting bolt 113and the threaded end 103 are arranged so that when disposed in aparallel axial position, they align with the corresponding bolt holes 79of the support beam 31 so that the support beam can be mounted thereonand accommodated within the recess 49 of the pedestal in a similarmanner to the previous embodiments, as shown in FIG. 7 of the drawings.

Assembly of the leg attachment system of the present embodiment isachieved by positioning the interlocking angles 91 into the track andsliding them into the juxtaposed corresponding position as previouslydescribed. The posterior tie means is then positioned upon theinterlocking angles and the pin 111 inserted through the alignedapertures.

The pedestal 25 is then positioned over the posterior tie means tosurmount the anchoring means and to sit upon the track.

The anterior tie means comprising the mounting bolt is then insertedinto position and the support beam is located upon the threaded ends ofthe respective anterior and posterior ties. The fastening nuts andwashers are then screwed onto the respective threaded ends of the ties,and the support beam, pedestal and anchoring means are all locked intoposition.

The above arrangement, although providing impact resistance loads inexcess of the prior art and meeting minimum standards of theInternational Maritime Organisation, is somewhat inferior to the legattachment systems described in the preceding embodiments.

The principal reason for this is that the posterior tie means takes mostof the impact load upon application of a lateral force, and hence is notas efficient in distributing the load to the foot of the anchoring meansand to the pedestal as is the case in the preceding embodiments.Consequently, the impact load resistance of this form of leg attachmentsystem is principally limited by the strength of the shank portion toresisting shear forces applied principally at the fastener end.

Notwithstanding the above, it should be appreciated that the presentembodiment still represents a significant advance over prior art legattachment systems and can have utility where this type of legattachment system is preferred to that of the preceding embodiments.

It should be appreciated that the scope of the present invention is notlimited to the particular embodiments herein described and that changesand modifications to the embodiments can be made without departing fromthe spirit or scope of the invention.

Moreover, where it is desirable to achieve an increased dampening effecton the resistance of the leg attachment system to impact or inertialforces applied to the seat, modifications can be made to the tie meansand anchoring means to provide the same. One way of achieving this is toreplace the posterior tie strap of the first and second embodiments witha structural member which extends inelastically under tensile loadsbeyond the normal load range during service. Such a device may be apreformed metal strap having a concertinaed shank portion as illustratedin FIGS. 16a and 16b of the drawings, or an alternative metal straphaving a perforated shank portion as illustrated in FIG. 17 of thedrawings.

Attachment of either of these extensible straps can be convenientlyaccommodated between the two interlocking angles using a simplearrangement of pins as described in the preceding embodiments.

In a further modification to the embodiments, an inextensible strapcould be fastened by deformable pins as illustrated in FIGS. 18a and 18bof the drawings, or deformable slots as illustrated in FIG. 19, ordeformable interlocking angles to allow controlled movement of the seatleg assembly at defined loads, but without separation of the components.

A further modification would be a combination using either of the twoaforementioned modifications.

We claim:
 1. A leg attachment for seats mounted to a seat support,including:an anchoring means for lockingly engaging a base having atrack therein, said base being fixedly mounted to a support; leg meansfor surmounting said anchoring means and supporting a seat supportthereon; and tie means having a first end and a second end forreleasable fixed attachment to said anchoring means at said first endand clamped locking engagement to the seat support at said second end,such that increased locking engagement of said tie means with the seatsupport positively locks said leg means relative to said anchoring meansand said base; wherein lateral forces applied to the seat support aretransferred by said leg means and said tie means to said anchoringmeans, whilst simultaneously being disseminated through said leg means;and wherein said anchoring means is adapted to dissipate the forcetransferred thereto substantially uniformly over an expansive portion ofthe base.
 2. A leg attachment as claimed in claim 1 wherein, saidanchoring means comprises a pair of interlocking angles, each having anouter flanged end, for being positively engaged within a longitudinallyextending cavity centrally disposed within and circumscribed by aC-shaped channel portion of the track, and a substantially planar webportion for projecting outwardly from the cavity; wherein said flangedends combinedly define a T-shaped foot for locking engagement within thecavity and said web portions define a leg for attachment to said tiemeans, when said interlocking angles are brought into juxtaposition witheach other.
 3. A leg attachment as claimed in claim 2, wherein, acombined transverse extent of said flanged ends is marginally less thana corresponding maximal transverse extent of the cavity, and a combinedtransverse extent of the web portions proximate to said foot ismarginally less than a minimal transverse extent of the cavity, so thatsaid interlocking angles are required to be transversely spaced apart aprescribed distance to fully occupy and engage said cavity when in saidjuxtaposition, to enable one interlocking angle to be discretelywithdrawn from engagement with the track by lateral rotation thereofrelative to the other interlocking angle.
 4. A leg attachment as claimedin claim 3, wherein said leg means comprises a tubular pedestal having abase end for sitting upon the track whilst surmounting said anchoringmeans, and an opposing support end formed with a transversely extendingrecess of complementary shape to the seat support to accommodate alongitudinal portion of the seat support, transversely across saidpedestal, said pedestal being of substantially rectangular form having apair of opposing side panels interconnected by a pair of opposing endpanels, and wherein the corners between said side panels and end panelsare truncated such that the breadth of said end panels is commensurateto said combined transverse extent of said web portions, so as to locatesaid pedestal centrally and symmetrically upon the track whensurmounting said anchoring means.
 5. A leg attachment as claimed inclaim 4, wherein said pedestal is formed with a rectangular aperture ina posterior end panel thereof, a prescribed distance from a bottom endof said pedestal, and said web portions are stepped at posterior endsthereof to define an outwardly projecting tongue correspondingly sizedto repose within said rectangular aperture.
 6. A leg attachment asclaimed in claim 4, wherein said pedestal is formed with a rectangularrecess in an anterior end panel thereof at a bottom end of saidpedestal, said rectangular recess extending a prescribed distance fromsaid bottom end to terminate at a prescribed height corresponding to atop of said interlocking angles thereat and said interlocking angleshave a length longer that a distance between said end panels, beingprovided with tapered anterior ends extending anteriorly beyond the saidpedestal through said rectangular recess so that said pedestal surmountsboth said interlocking angles simultaneously.
 7. A leg attachment asclaimed in claim 2, wherein, said web portions are each provided with acorresponding transversely extending aperture to facilitate attachmentto said tie means.
 8. A leg attachment as claimed in claim 7, whereinsaid first end is able to be releasably pinned to said anchoring meansby means of a pin inserted through corresponding apertures of said webportions and said one end when brought into relative axial alignment. 9.A leg attachment as claimed in claim 8, wherein the length of said pinis commensurate to the corresponding transverse spacing between saidpanel sides.
 10. A leg attachment as claimed in claim 7, wherein a pairof said apertures is disposed anteriorly of said web portions and afurther aperture is disposed forwardly of said web portions, relative tosaid track, said pair of apertures being disposed in horizontally spacedrelation to each other to strengthen the attachment of said web portionsto said tie means.
 11. A leg attachment as claimed in claim 1, whereinsaid leg means comprises a tubular pedestal having a base end forsifting upon the track whilst surmounting said anchoring means, and anopposing support end formed with a transversely extending recess ofcomplementary shape to the seat support to accommodate a longitudinalportion of the seat support, transversely across said pedestal.
 12. Aleg attachment as claimed in claim 11, wherein said tie means comprisesa shank portion for extending along and within said pedestal, said firstend having a transversely extending aperture for aligning withcorresponding apertures of said anchoring means to facilitate attachmentthereto.
 13. A leg attachment as claimed in claim 12, wherein said shankportion comprises a strap of commensurate transverse extent at saidfirst end to a prescribed distance for being disposed interposedlybetween said web portions, so as to maintain locking engagement of saidfoot with the track.
 14. A leg attachment as claimed in claim 11,wherein said second end of said tie means is formed with a screwthreaded fastening means for locating within a corresponding aperturedisposed upon said seat support and for clampingly and lockinglyengaging the seat support positively upon said pedestal within saidrecess on increased locking engagement of said fastening means upon theseat support.
 15. A leg attachment system for seats mounted to a seatsupport, including:a base having a track for fixed mounting to asupport; and a leg attachment including:(i) an anchoring means forlockingly engaging said track; (ii) leg means for surmounting saidanchoring means and supporting a seat support thereon; and (iii) tiemeans having a first end a second end, for releasable fixed attachmentto said anchoring means at said first end and clamped engagement to theseat support at said second end, such that increased locking engagementof said tie means with the seat support positively locks said leg meansrelative to said anchoring means and said base; wherein lateral forcesapplied to the seat support are transferred by said leg means and saidtie mans to said anchoring means, whilst simultaneously beingdisseminated through said leg means; and wherein said anchoring means isadapted to dissipate the force transferred thereto uniformly over anexpansive portion of said base.
 16. A method of forming a leg attachmentsystem for seats, comprising:fixedly mounting a base having a tracktherein to a support; inserting anchoring means into said track tolockingly engage therewith; releasedly attaching tie means to saidanchoring means, so that said tie means can project upwardly therefrom;surmounting a leg means for supporting a seat support, over saidanchoring means so that said tie means is disposed within the leg meansand can extend therealong; positioning a seat support upon said legmeans and locating a portion of said tie means to extend through saidseat support; and clampingly engaging said seat support to said legmeans by locking engagement of said tie means with said seat support,and consequently clampingly engaging said leg means upon said track;wherein lateral forces applied to said seat support are transferred bysaid leg means and said tie means to said anchoring means, whilstsimultaneously being disseminated through said leg means; and whereinforces transferred to said anchoring means are dissipated uniformly overan expansive portion of said base.